Summer Research

Each summer, students and faculty carry-out collaborative research. In some cases students volunteer their time and assist faculty with ongoing projects or intiate their own novel lines of research. Students can also apply for summer research funding through various internal and external fellowship and granting agencies (see below). Finally, when funds are available, faculty may hire students to conduct summer research.

Previous Summer Research Awards

2015

Hannah Baumgartner

Effect of spatial attention on early visual processing in the primary visual cortex[More Info]

Abstract

The present study aimed to examine whether spatial attention can modulate visual processing at the earliest cortical level of sensory processing. While it is well known that attention can selectively modify visual processing, the cutoff for where in the neural pathway this effect first manifests has been the topic of intense debate. Many studies find that the initial phase of processing in primary visual cortex (40-60 msec poststimulus onset) is unaffected by attention. This suggests a rich detailed cortical representation of the visual world, at least during initial stages of sensory processing. A handful of recent experiments, however, suggest that spatial attention can selectively modulate processing as early as 40-60 msec in primary visual cortex (V1). The present study aimed to replicate and extend one of the most promising experiments that finds early attentional effects on sensory processing in V1 [1]. Subjects performed a visuospatial attention task while electrophysiological brain activity was recorded via scalp EEG. Importantly, stimulus locations and electrode positions were customized for each individual subject in order to account for variations in electrical signal strength due to neuroanatomical differences. Preliminary results suggest that spatial attention does not influence visual processing at this early level, though more data collection is required to confirm this finding.

Hayley VanderJagt

This study intended to investigate the nature of processing of multiple adjectives via the recording of brain activity elicited by sentences containing contradictory sequences that appear to violate grammatical-semantic constraints (e.g. “the small big dog chased the ball”). In a prior study using similar sentences, Kemmerer et. al. (2007) found a reduced N400 and an enhanced P600 at the 2nd adjective (e.g. big) proposing that these effects reflect semantic and syntactic aspects of a temporary reanalysis. Our study tested this proposal by presenting 3 types of contexts containing high, low, or no licensing information prior to the critical sentence. If Kemmerer et. al. are correct, we proposed that the P600 and N400 effects should disappear or decrease considerably when sentences follow licensing (high information) contexts. In contrast, if the effects remained, alternative accounts based on a syntactic-semantic reanalysis would be supported. Our study also introduced a broader range of adjective types than Kemmerer et al., to explore whether the N400/P600 effects are a general effect of contradictory adjectives or whether this is an effect of the relative interpretation of dimension adjectives (e.g. big/small).

2014

Fenner Macrae

The role of abstract beliefs and neural oscillations in motor preparation and inhibition[More Info]

Abstract

The present study is a replication and extension of a recent experiment by Rigoni et al. (2011)which found that inducing disbelief in free will alters brain activity associated with preconscious motorpreparation. This finding is surprising because an abstract belief appears to have affected low-levelneural activity in the pre-motor cortex. The current study will help to determine whether this finding isgenuine by replicating the procedures and analyses of the original study. We will also investigatewhether pre-existing beliefs concerning free will influence brain activity in a similar manner to inducedbeliefs. In a separate experiment Rigoni et al. (2012) found that inducing disbelief in free will loweredsubjects' propensity to inhibit prepared motor responses. In the present study, we will examine neuralcorrelates of aborting a planned motor action to determine whether Rigoni et al.’s (2012) behavioralobservation corresponds to a difference in neural oscillatory activity previously associated with motorinhibition.

2013

Christian Graulty

The present study aims to investigate brain plasticity in intact individuals by recording brain activity elicited by auditory ‘soundscapes’ before and after undergoing sensory substitution training. Such training allows subjects to extract shape information from auditory stimuli. The success of the sensory substitution procedure will be assessed in a task using novel sounds to identify novel shapes. We aim to examine the time course of lateral occipital complex activity in shape processing and assess how it is modulated by cross-modal neuroplasticity.

Enriqueta Canseco-Gonzalez

Electrophysiological dynamics of cross-modal plasticity in the lateral occipital complex due to sensory substitution training[More Info]

Abstract

We investigate brain plasticity in intact individuals by recording their brain activity elicited by auditory ‘soundscapes’ before and after undergoing sensory substitution training. Such training allows subjects to extract shape information from auditory stimuli. The success of the sensory substitution procedure will be assessed in a task using novel sounds to identify novel shapes. We hope to demonstrate the time course of lateral occipital complex activity in shape processing (regardless of modality) and assess how it is modulated by cross-modal plasticity.

2012

Kathryn Schelonka

Previous studies have suggested that linguistic information is processed differently from non-linguistic sounds at early and late stages of auditory perception; however, the neural mechanisms responsible for discrimination between speech and non-speech sounds have been notoriously difficult to identify due to the physical acoustic differences between speech and non-speech stimuli. Sine-wave speech (SWS) is a unique auditory phenomenon in which the same physical stimulus can be perceived as noise or as speech depending on perceptual expectations. In this study we compared event-related potentials (ERPs) elicited by SWS stimuli in both non-speech and speech conditions. Participants completed a discrimination task between four SWS sounds before and after they had been trained to hear the sounds as speech. We found that the N1 auditory component was larger in the non-speech condition, likely reflecting increased attentional demands for the more difficult task of sound discrimination compared to speech discrimination. The speech and non-speech elicited ERPs also diverged around 300 ms over the frontal scalp, resulting in a lasting positive shift in the speech condition compared to the non-speech condition. This latter difference may reflect upper-level speech processes. Follow-up studies controlling for task difficulty and word repetition will also be discussed.

Loretta Yiu

An electrophysiological study on the time course of bilingual word recognition[More Info]

Abstract

Current theories of monolingual language comprehension suggest that phonological processing precedes semantic information, which in turn precedes syntactic information. Bilingual language comprehension likely requires an additional level: knowledge of which language a specific word belongs to. The Revised Bilingual Interactive Activation (BIA+) model of word recognition proposes that bilinguals use language ‘tags,’ that is, information identifying the specific language of a word, to help them monitor the appropriate language of use at any given time (Dijkstra & van Heuven, 2002). A central question then is when exactly this language ‘tag’ information becomes available during language comprehension. Using the recording of event-related potentials, we investigated the time course of semantic and language ‘tag’ encoding during visual word recognition. Spanish-English bilinguals viewed a series of printed words while making dual-choice go/nogo and left/right hand decisions based on semantic (whether the word was an object or an animal) and language ‘tag’ information (whether the word was in English or Spanish). According to initial findings, the onset latency of the N200 (a component related to response inhibition) indicated that language ‘tag’ information may be accessed as early as semantic information or soon after. This finding is compatible with the BIA+ model, supporting the claim that language ‘tag’ information is accessed relatively late (i.e. compared to phonological information) during bilingual word recognition. That is, the language ‘tag’ information may come too late to filter out words inappropriate to the current language context.